<!DOCTYPE html>
<html lang="en">
	<head>
		<title> three.js webgl - ShadowMesh </title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				background-color: rgb(0, 0, 0);
				margin: 0;
				padding: 0;
				overflow: hidden;
			}

			#lightButton {
				position: absolute;
				right: 20px;
				top: 20px;
			}
		</style>
	</head>
	<body>

		<div id="container"></div>
		<input id="lightButton" type="button" value="Switch to PointLight" onclick="lightButtonHandler()">

		<script src="../build/three.js"></script>
		<script src="js/objects/ShadowMesh.js"></script>
		<script>

			var SCREEN_WIDTH = window.innerWidth;
			var SCREEN_HEIGHT = window.innerHeight;

			var scene = new THREE.Scene();
			var camera = new THREE.PerspectiveCamera( 55, SCREEN_WIDTH / SCREEN_HEIGHT, 1, 3000 );
			var clock = new THREE.Clock();
			var renderer = new THREE.WebGLRenderer();

			var sunLight = new THREE.DirectionalLight( 'rgb(255,255,255)', 1 );
			var useDirectionalLight = true;
			var arrowHelper1, arrowHelper2, arrowHelper3;
			var arrowDirection = new THREE.Vector3();
			var arrowPosition1 = new THREE.Vector3();
			var arrowPosition2 = new THREE.Vector3();
			var arrowPosition3 = new THREE.Vector3();
			var groundMesh;
			var lightSphere, lightHolder;
			var pyramid, pyramidShadow;
			var sphere, sphereShadow;
			var box, boxShadow;
			var cube, cubeShadow;
			var cylinder, cylinderShadow;
			var torus, torusShadow;
			var normalVector = new THREE.Vector3( 0, 1, 0 );
			var planeConstant = 0.01; // this value must be slightly higher than the groundMesh's y position of 0.0
			var groundPlane = new THREE.Plane( normalVector, planeConstant );
			var lightPosition4D = new THREE.Vector4();
			var verticalAngle = 0;
			var horizontalAngle = 0;
			var frameTime = 0;
			var TWO_PI = Math.PI * 2;

			init();
			animate();

			function init() {

				renderer.setClearColor( 'rgb(0,150,255)' );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );
				document.getElementById( "container" ).appendChild( renderer.domElement );
				window.addEventListener( 'resize' , onWindowResize, false );

				camera.position.set( 0, 2.5, 10 );
				scene.add( camera );
				onWindowResize();

				sunLight.position.set( 5, 7, - 1 );
				sunLight.lookAt( scene.position );
				scene.add( sunLight );

				lightPosition4D.x = sunLight.position.x;
				lightPosition4D.y = sunLight.position.y;
				lightPosition4D.z = sunLight.position.z;
				// amount of light-ray divergence. Ranging from:
				// 0.001 = sunlight(min divergence) to 1.0 = pointlight(max divergence)
				lightPosition4D.w = 0.001; // must be slightly greater than 0, due to 0 causing matrixInverse errors

				// YELLOW ARROW HELPERS
				arrowDirection.subVectors( scene.position, sunLight.position ).normalize();

				arrowPosition1.copy( sunLight.position );
				arrowHelper1 = new THREE.ArrowHelper( arrowDirection, arrowPosition1, 0.9, 0xffff00, 0.25, 0.08 );
				scene.add( arrowHelper1 );

				arrowPosition2.copy( sunLight.position ).add( new THREE.Vector3( 0, 0.2, 0 ) );
				arrowHelper2 = new THREE.ArrowHelper( arrowDirection, arrowPosition2, 0.9, 0xffff00, 0.25, 0.08 );
				scene.add( arrowHelper2 );

				arrowPosition3.copy( sunLight.position ).add( new THREE.Vector3( 0, - 0.2, 0 ) );
				arrowHelper3 = new THREE.ArrowHelper( arrowDirection, arrowPosition3, 0.9, 0xffff00, 0.25, 0.08 );
				scene.add( arrowHelper3 );

				// LIGHTBULB
				var lightSphereGeometry = new THREE.SphereGeometry( 0.09 );
				var lightSphereMaterial = new THREE.MeshBasicMaterial( { color: 'rgb(255,255,255)' } );
				lightSphere = new THREE.Mesh( lightSphereGeometry, lightSphereMaterial );
				scene.add( lightSphere );
				lightSphere.visible = false;

				var lightHolderGeometry = new THREE.CylinderGeometry( 0.05, 0.05, 0.13 );
				var lightHolderMaterial = new THREE.MeshBasicMaterial( { color: 'rgb(75,75,75)' } );
				lightHolder = new THREE.Mesh( lightHolderGeometry, lightHolderMaterial );
				scene.add( lightHolder );
				lightHolder.visible = false;

				// GROUND
				var groundGeometry = new THREE.BoxGeometry( 30, 0.01, 40 );
				var groundMaterial = new THREE.MeshLambertMaterial( { color: 'rgb(0,130,0)' } );
				groundMesh = new THREE.Mesh( groundGeometry, groundMaterial );
				groundMesh.position.y = 0.0; //this value must be slightly lower than the planeConstant (0.01) parameter above
				scene.add( groundMesh );

				// RED CUBE and CUBE's SHADOW
				var cubeGeometry = new THREE.BoxGeometry( 1, 1, 1 );
				var cubeMaterial = new THREE.MeshLambertMaterial( { color: 'rgb(255,0,0)', emissive: 0x200000 } );
				cube = new THREE.Mesh( cubeGeometry, cubeMaterial );
				cube.position.z = - 1;
				scene.add( cube );

				cubeShadow = new THREE.ShadowMesh( cube );
				scene.add( cubeShadow );

				// BLUE CYLINDER and CYLINDER's SHADOW
				var cylinderGeometry = new THREE.CylinderGeometry( 0.3, 0.3, 2 );
				var cylinderMaterial = new THREE.MeshPhongMaterial( { color: 'rgb(0,0,255)', emissive: 0x000020 } );
				cylinder = new THREE.Mesh( cylinderGeometry, cylinderMaterial );
				cylinder.position.z = - 2.5;
				scene.add( cylinder );

				cylinderShadow = new THREE.ShadowMesh( cylinder );
				scene.add( cylinderShadow );

				// MAGENTA TORUS and TORUS' SHADOW
				var torusGeometry = new THREE.TorusGeometry( 1, 0.2, 10, 16, TWO_PI );
				var torusMaterial = new THREE.MeshPhongMaterial( { color: 'rgb(255,0,255)', emissive: 0x200020 } );
				torus = new THREE.Mesh( torusGeometry, torusMaterial );
				torus.position.z = - 6;
				scene.add( torus );

				torusShadow = new THREE.ShadowMesh( torus );
				scene.add( torusShadow );

				// WHITE SPHERE and SPHERE'S SHADOW
				var sphereGeometry = new THREE.SphereGeometry( 0.5, 20, 10 );
				var sphereMaterial = new THREE.MeshPhongMaterial( { color: 'rgb(255,255,255)', emissive: 0x222222 } );
				sphere = new THREE.Mesh( sphereGeometry, sphereMaterial );
				sphere.position.set( 4, 0.5, 2 );
				scene.add( sphere );

				sphereShadow = new THREE.ShadowMesh( sphere );
				scene.add( sphereShadow );

				// YELLOW PYRAMID and PYRAMID'S SHADOW
				var pyramidGeometry = new THREE.CylinderGeometry( 0, 0.5, 2, 4 );
				var pyramidMaterial = new THREE.MeshPhongMaterial( { color: 'rgb(255,255,0)', emissive: 0x440000, shading: THREE.FlatShading, shininess: 0 } );
				pyramid = new THREE.Mesh( pyramidGeometry, pyramidMaterial );
				pyramid.position.set( - 4, 1, 2 );
				scene.add( pyramid );

				pyramidShadow = new THREE.ShadowMesh( pyramid );
				scene.add( pyramidShadow );

			}

			function animate() {

				requestAnimationFrame( animate );

				frameTime = clock.getDelta();

				cube.rotation.x += 1.0 * frameTime;
				cube.rotation.y += 1.0 * frameTime;

				cylinder.rotation.y += 1.0 * frameTime;
				cylinder.rotation.z -= 1.0 * frameTime;

				torus.rotation.x -= 1.0 * frameTime;
				torus.rotation.y -= 1.0 * frameTime;

				pyramid.rotation.y += 0.5 * frameTime;

				horizontalAngle += 0.5 * frameTime;
				if ( horizontalAngle > TWO_PI )
					horizontalAngle -= TWO_PI;
				cube.position.x = Math.sin( horizontalAngle ) * 4;
				cylinder.position.x = Math.sin( horizontalAngle ) * - 4;
				torus.position.x = Math.cos( horizontalAngle ) * 4;

				verticalAngle += 1.5 * frameTime;
				if ( verticalAngle > TWO_PI )
					verticalAngle -= TWO_PI;
				cube.position.y = Math.sin( verticalAngle ) * 2 + 2.9;
				cylinder.position.y = Math.sin( verticalAngle ) * 2 + 3.1;
				torus.position.y = Math.cos( verticalAngle ) * 2 + 3.3;

				// update the ShadowMeshes to follow their shadow-casting objects
				cubeShadow.update( groundPlane, lightPosition4D );
				cylinderShadow.update( groundPlane, lightPosition4D );
				torusShadow.update( groundPlane, lightPosition4D );
				sphereShadow.update( groundPlane, lightPosition4D );
				pyramidShadow.update( groundPlane, lightPosition4D );


				renderer.render( scene, camera );


			}

			function onWindowResize() {

				SCREEN_WIDTH = window.innerWidth;
				SCREEN_HEIGHT = window.innerHeight;

				renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );

				camera.aspect = SCREEN_WIDTH / SCREEN_HEIGHT;
				camera.updateProjectionMatrix();

			}

			function lightButtonHandler() {

				useDirectionalLight = !useDirectionalLight;

				if ( useDirectionalLight ) {

					renderer.setClearColor( 'rgb(0,150,255)' );
					groundMesh.material.color.set( 'rgb(0,130,0)' );
					sunLight.position.set( 5, 7, - 1 );
					sunLight.lookAt( scene.position );

					lightPosition4D.x = sunLight.position.x;
					lightPosition4D.y = sunLight.position.y;
					lightPosition4D.z = sunLight.position.z;
					lightPosition4D.w = 0.001; // more of a directional Light value

					arrowHelper1.visible = true;
					arrowHelper2.visible = true;
					arrowHelper3.visible = true;

					lightSphere.visible = false;
					lightHolder.visible = false;

					document.getElementById( 'lightButton' ).value = "Switch to PointLight" ;

				} else {

					renderer.setClearColor( 'rgb(0,0,0)' );
					groundMesh.material.color.set( 'rgb(150,150,150)' );

					sunLight.position.set( 0, 6, - 2 );
					sunLight.lookAt( scene.position );
					lightSphere.position.copy( sunLight.position );
					lightHolder.position.copy( lightSphere.position );
					lightHolder.position.y += 0.12;

					lightPosition4D.x = sunLight.position.x;
					lightPosition4D.y = sunLight.position.y;
					lightPosition4D.z = sunLight.position.z;
					lightPosition4D.w = 0.9; // more of a point Light value

					arrowHelper1.visible = false;
					arrowHelper2.visible = false;
					arrowHelper3.visible = false;

					lightSphere.visible = true;
					lightHolder.visible = true;

					document.getElementById( 'lightButton' ).value = "Switch to DirectionalLight" ;

				}

			}

		</script>
	</body>
</html>
